Heriksen Higashi Puerari

Reaction of vegetables and aromatic plants to Meloidogyne javanica and M. incognita

For this research we used 15 day-old seedlings which were transplanted to 2 L pots and inoculated with 4,000 nematode eggs plus juveniles (J2). After 60 days, the root systems were removed and the number of galls and eggs evaluated and used to calculate the nematode reproduction factor (RF). The tomato cv. Santa Cruz was used as a susceptible control. The experimental design was completely randomized, with six replications. Averages were compared using the Tukey or Scott-Knott test at 5%. For lettuce, Salad Bowl (Mimosa type), Elizabeth and Elisa (Lisa) and Vera cultivars (crisphead), the number of galls and the RF for M. javanica were statistically higher than for the control, whereas, for the other vegetable crops, the highest number of galls and eggs were found in chicory and basil. The highest susceptibility to M. incognita was observed in Mimosa lettuce cv. Salad Bowl, chicory cultivars, parsley cv. Grauda Portuguesa and basil. Marjoram exhibited no M. incognita galls.

Resistance inducers in the control of root lesion nematodes in resistant and susceptible cultivars of maize

Pratylenchus brachyurus stands out among the major importance nematodes for the national agriculture, due your difficulty of control. Thus, the study aimed to evaluate the efficiency of resistance inductors in the nematode management in resistant and susceptible maize. It was studied the inductors acibenzolar-S-metil, Ecolife™ and manganese phosphite. The experiment was conducted in a factorial arrangement (2 × 4) composed for two maize genotypes (resistant and susceptible to nematode). Each inductor was applied, singly, seven days and one day before inoculation and seven days after inoculation to nematode. Untreated plants were used as control. The inductor Acibenzolar-S-metil was efficient to reduce the nematode population in both genotypes. Ecolife™ promoted the nematode reduction in susceptible genotype while the results were variable for manganese phosphite. In general, the inductors showed no significant effect on plant development and the same factor mainly affected by genotype.

Acibenzolar-S-methyl on Meloidogyne javanica control in lettuce

ABSTRACT Nematodes are among the main limiting factors of the vegetables productivity, especially due to management restriction this crop to obtain an efficient control of pathogen. Resistance induction using acibenzolar-S-methyl (ASM) has presented promising results in the management of diseases, but to plant-parasitic nematodes the time required to activate latent defense mechanisms is a limiting factor, which can be prevented with the treatment of seedlings in trays. Thus, the present study aimed to assess different times of ASM application to Meloidogyne javanica control in lettuce. Lettuce seedlings were produced in trays, transplanted to pots 25 days after germination and inoculated with 2000 eggs of the nematode. The seedlings were pulverized on shoots with ASM 10 or 5 days before of transplant (DBT), on the day of transplant (DT), 5 or 10 days after transplant (5 or 10 DAT), 10 DBT + DT and 10 DBT + 5 DAT. The untreated plants formed the control group. Fifty days later, these plants were collected and evaluated the nematological and vegetative parameters. The treatments promoted a decrease in M. javanica population higher than 60% when applied until 5 DAT and generally did not interfere with the vegetative parameters of lettuce, and ASM can be adopted as an alternative for the root-knot nematodes management.

Sucessão crambe-soja no manejo de Pratylenchus brachyurus e Meloidogyne javanica

Crop succession system implementation, which allows the introduction of plant species that are antagonists or non-hosts for soybean pathogens during the intercrop period, is a sustainable alternative in crop systems. Thus, careful selection of succession plants is recommended to ensure that they do not allow the proliferation of nematodes, especially the soybean parasites Pratylenchus brachyurus and Meloidogyne javanica. The aim of this study was to assess P. brachyurus and M. javanica population reduction potential by growing species in succession with soybean, comparing them to crambe. Soybean seeds cv. 5909RR Nidera were sown in 18-L pots, and after fifteen days inoculations were performed in separate experiments, with 1000 specimens of P. brachyurus and Tavares-Silva, C.A.; Dias-Arieira, C.R.; Puerari, H.H.; Silva E.J.; Izidoro Junior, A. Crambe – soybean succession on the management of Pratylenchus brachyurus and Meloidogyne javanica. Summa Phytopathologica, v.43, n.4, p.316-320, 2017. 3000 eggs and possible second-stage juveniles (J2) of M. javanica. At 60 days after inoculation, the shoot of soybean plants was discarded, and the succession crops (maize cv. IPR114, bean cv. IPR Tangará, oilseed radish, black oat cv. IAPAR 61 and crambe cv. MS Brilhante) were sown. Plants were cultivated for 90 days, when the shoot was removed, and soybean cultivar was sown again and cultivated for additional 60 days. At the end of this period, plants were removed from the pots for determination of vegetative and nematological parameters for soybean. Crambe introduction in the crop succession system effectively reduced P. brachyurus population. M. javanica reproduction was lower for crambe compared to the remaining systems, but its reproductive factor was high.

Acibenzolar-S-methyl doses and application methods to Pratylenchus brachyurus control in maize

ABSTRACT Pratylenchus brachyurus is one of the main limiting factors of agricultural yield in annual crops, particularly due its difficult management. Methods to reduce populations are constantly sought, and the use of resistance inducers deserves attention. Thus, the study aimed to assess the effect of acibenzolar-S-methyl (ASM) application in different doses to P. brachyurus control in maize. Initially, 1000 specimens of P. brachyurus were inoculated in maize for the multiplication. After 60 days, the aerial part (AP) was discarded and maize was sown under the treatments: seed treatment (ST), application in the AP and ST + AP, in the doses of 0.125, 0.25, 0.5 and 1.0 g i.a./L. Vegetative and nematological parameters were assessed 60 days later. ASM did not affect plant growth, but reduced nematode population in all the treatments. The treatment methods did not differ and reduced the number of nematodes/g root by 64.25 to 80.14% compared to the control. The doses of 0.6, 0.51 and 0.65 g i.a./L promoted the most reductions in the number of nematodes/g root when applied in ST, AP and ST + AP, respectively. Thus, we recommend the use of ASM applied on shoot in a dose of 0.50 g i.a./L.

Boron and zinc inhibit embryonic development, hatching and reproduction of Meloidogyne incognita

ABSTRACT Nematodes have difficult control and complex handling, but considering the physiological and biochemical changes that micronutrients promoting in plants, there is possibility that the supply with these chemicals increases the resistance of plants against nematodes. Thus, the present study aimed to assess the effect of the application of boron and zinc on the reproduction of Meloidogyne incognita, embryonic development and juvenile nematode hatching. Nematode reproduction was evaluated in tomato plant inoculated with 2000 eggs and treated in the aerial part with boron or zinc at the following doses: 0, 1/2, 1×, 2× and 4× the manufacturers recommendation (100 and 30 g/L, respectively), with the plants assessed 60 days after inoculation. For assessment of embryonic development and juvenile hatching, 1 mL nematode suspension was placed in Petri dishes containing 9 mL of the same doses of boron and zinc, and assessment occurred four and eight days after incubation. Results obtained showed that boron controlled nematode population at the dose of 400 g/L and promoted juvenile hatching when used at maximum dosage on the eighth day. Zinc reduced the number of galls and the number of eggs at the dose of 60 g/L, but did not exhibit direct effect on nematode.

Reação de porta-enxertos de videira a Pratylenchus brachyurus e Pratylenchus zeae

The aim of this study was to evaluate the reaction of eight grapevine rootstocks to root-lesion nematodes. Cuttings of the rootstocks Kober, SO4, 101-14, R99, 420-A, Rupestris du Lot, Riparia do Traviu and Telek 5C, provided by the Centro APTA de Frutas/IAC, were planted in 5-L pots containing a 2:1 (v:v) soil and sand mixture, and kept in greenhouse. After four months, they were inoculated with 1,200 specimens of Pratylenchus brachyurus or P. zeae. Maize was used for detecting the inoculum viability. After 180 days of the inoculation, the root systems of the plants were collected along with 100 cm3 soil for evaluating the number of nematodes. Maize plants were evaluated 90 days after inoculation and each pot received a new seedling, which was evaluated along with the rootstocks. All rootstocks exhibited immunity to P. brachyurus and P. zeae, because the final populations in the root systems and the reproduction factor were zero. It was recovered six and 11 specimens of P. zeae in samples from cultivated soil with Kober and 420-A rootstock, respectively. In the maize, the respective average populations of P. brachyurus and P. zeae were 8,040 and 6,940. The rootstocks are potentially valuable for infested areas.